Electrical spider connection



Sept. 23, 1969 c, BROOM ET AL ELECTRICAL SPIDER CONNECTION Filed Dec. 6,'1965 all!!! By 3466!," k

INVENTOR. ,fl, 3400M 1%.777/[46' United States Patent 3,469,020ELECTRICAL SPIDER CONNECTION Charles M. Broom, Coral Gables, and RobertH. Stevens, Miami, Fla., assignors to Kearney-National Inc., St. Louis,Mo., a corporation of Delaware Filed Dec. 6, 1965, Ser. No. 511,648 Int.Cl. H02g 3/28, 15/08 U.S. Cl. 17471 9 Claims ABSTRACT OF THE DISCLOSUREA device for facilitating the making of electrical connections in tightplaces between a main line conductor and a multiplicity of branchcircuit lines wherein a multiplicity of relatively short pieces ofinsulated conductor, long enough to reach out of the tight place, allhave an end barren of insulation permanently mechanically andelectrically connected together with a line conductor terminal and thejunction embedded in insulation.

buildings.

The present novel spider connection provides a rigid hermetically sealedconnection that develops the full potential strength of the conductors;i.e., the connection will hold under a tension that causes theindividual conductors to fail. The spider connection may be made usingthe main feeder conductor and the multiple branch circuits as the legsof the spider, whereby additional splicing is avoided. Alternatively,the spider may be fabricated in the 'shop and later spliced into themain and branch circuits using methods commonly known to those skilledin the art.

An object of this invention is to provide an insulated electricalconnector having improved means for connecting a multiplicity of branchcircuits to a common supply. "Another object of this invention is toprovide an improved connector having superior mechanical and electricalcapabilities that can be field assembled by the average' workman.

E further object of this invention is to provide a novel and improvedelectrical connector that is of extremely simple construction, requiringonly a minimum of basic materials of construction for fabrication, andwhich is adapted to be used for wet or dry locations.

Still another object of this invention is to provide an insulatedelectrical connector that can be' shop assembled using ordinary toolsand supplies and which is adapted -toinclude various sizes and numbersof wires and wherein the terminal ends of the Wires provide a junctionthat is adapted-to connect from a main to a number of branch circuits.

Still'another object of this invention is to provide a '-means forreadily connecting a power main to a plurality of branches, especiallyin the field where the assembling may take place in cramped quarters.

This and other'objects and features of this invention {will be madevmore apparentby reference to the follow- 3,469,020 Patented Sept. 23,1969 ing description taken in conjunction with the accompanyingdrawings, in which:

FIGURE 1 is a part sectional, part perspective view of an electricalconnector illustrating one embodiment of the electrical spiderconnection.

FIGURE 2 is a top perspective view of the connector of FIGURE 1.

FIGURE 3 is a sectional view of another embodiment of the inventionshowing a modification of the improved connector of FIGURES 1 and 2.

Looking now in detail to the drawings, wherein like numerals indicatesimilar elements in the different figures, there is seen in FIGURES 1and 2 a spider connection 1 comprised of six insulated conductors 3having metallic wires 5, 6, and 7, each being joined at one end into arigid terminal connection 2. As best seen in FIGURE 1, the terminalconnection 2 comprises the cable bundle, or the six wires 5, 6, and 7tightly wrapped with wire at several locations, as seen at 8, to form arigid mechanical connection which is encased in solder. After the solderhas sufficiently cooled, the entire spider connection is molded orencased in an epoxy potting compound as seen at 10.

In making the above first mechanical connection, the wires of theindividual conductors 3 have been stripped of their insulation as shownat 5, 6, and 7 to present a clean surface that can be suitably solderedwith no additional preparation being required. Where a Wire size number2 is used for the spider conductor 5, 6, and 7, the mechanically wrappedjoint or connection may be satisfactorly effected by employing eightturns of number 18 copper wire at four equally spaced positions startingabout inch from the end of the connection and completing the wrap aboutone inch from the end. The insulation is left as illustrated at 16 toprovide a hermetic seal between the various conductors.

The mechanical terminal connection is next encased in solder as at 9,using conventional means such as a small mold wherein solder is pouredfrom a ladle into the mold. The surface of the conductor bundle maypreferably be tinned prior to soldering, if desired, especially where ahigh lead content of the solder 9 is used. The molded connection 9,except for extremely large conductors, can be immediately placed in asuitable second mold for the pouring of the epoxy compound 10, since thetemperature of the connection 9 will usually have dropped to a suitablevalue during the preparation of this final step.

During the initial preparation of the individual conductors 3, theinsulation at 16 should be roughened by scraping or sanding to permitattaining a bond between the epoxy compound and the insulation. In thespecific above example wherein No. 2 wire is used, about /2 inchinsulation should be embedded in the epoxy resin. The resin isadvantageously poured into a pre-formed uncoated paper mold or into awaxed or Teflon coated paper mold Which may be either left in place aspart of the connection means or removed for further use as desired. Theepoxy will not bond to a new Teflon" coated mold; but, as the Teflonmold is subjected to abuse and becomes scarred on the inside fromrepeated use, it becomes more difficult to remove from the spiderconnection from such a mold and where its presence may proveadvantageous the mold may be left as part of the spider connection tooffer further protection to the assembly. Dyes may be employed in theepoxy resins to additionally color code the spider connection, which mayalso have color coded insulation thereon.

3 Where thespider connection of FIGURES l and 2 is to be used to spliceinto a large cable run, that is a Y or inline splice, that is attachedat the midpoint of a cable rather than the end thereof, the two largeconductors 6 and 7 may be sized equal to the diameter of the cable run,and two conductors 6 and 7 placed in series with the tapped cable. Theinline splice may also be made merely by cutting the main conductor andusing each end of the main as represented by conductors 6 and 7, wherethe spider is made on site in the field. Alternatively, a single largerconductor 6 or 7, FIGURES 1 and 2, may be attached to a line cable as bya so-called H-frame compression connector of ductile metal such as acopper or aluminum, and then insulating the connection in accordancewith the principles outlined above.

In the embodiment depicted by FIGURE 3, a copper sleeve 13, with orwithout an intermediate barrier 12 therein, is employed foraccommodating the multiplicity of branch line conductors 5 at one end14, and for confining one or more main conductors at the other end. Thesleeve 13 may be a compression connector which, after assembly thereinof the ends of a multiplicity of conductors 5, is compressed about theminto a strong mechanical connection with good electrical conductivity.If desired, the connection may be further strengthened by soldering asat 9. Alternatively, the conductors 5 may be welded or otherwise securedin the end 14 of the sleeve with or without compressing the sleeve aboutthe conductors. In any event, after the conductors 5 are suitablymechanically and electrically connected to the sleeve, the connection ispreferably encased in an epoxy resin embedment as illustrated at 10 toprovide a field assembled or shop assembled spider connection 2.Likewise, the common at aperture 15 may be connected in any suitable wayto an incoming main while conductors 3 feed individual circuits orbranches as desired. For example, the common at aperture 15 may becompressed onto one or more large incoming service conductors, and, ifdesired, reinforced as with solder and embedded in insulation resin, asabove outlined, depending upon the conditions of its intended use. Infact, the sleeve 13 may itself be the main conductor, or part thereof.

The caps 4 of FIGURES 1 through 3 are left in place to protect theconductors from the deleterious effects of the atmosphere in which theyare used. In some circuitry applications, only a portion of the severalspider connections may be initially used, hence the remaining spiderconductors will be available for future use, as occasion demands, bymerely removing the cap and making a straight splice type connection,such as by employing an H-frame or sleeve type compression connector orother conventional branch with adequate insulation for the particularusage.

' Regardless of the manner in which the component main and branchconductors are mechanically and electrically connected together into thespider, the legs, e.g., conductors 5, 6, and 7, are of no greater lengththan will be convenient for a lineman to handle and install, and suchwill ordinarilymean the legs, whether large or small, be of length nogreater than about four feet.

I The epoxy resin referred to herein is basically the same type materialused in the more advanced type insulation of motor coils, condensers,transformers, and the like, and one suitable resin employed was found tohave the following properties:

Flexural modulus of elasticityp.s.i. (5.92)(l Tensile strength p.s.i8,500 Compressive strength p.s.i 23,000 Dielectric const. at 60 c.'p.s2.93 Specific gravity 1.11

Corp. formula HU-l65 is suitable, as is ordinary fiberglass resin, likethat used in the re'pair'of boats where fiberglass textile is built upusing the resin.

It is now evident that each of the above novel spider connections offersan inexpensive means of supplying several branch circuits from a singleservice conduit, wherein the spider connection also provides a fieldassembled connector that is strong both electrically and mechanically,and will additionally provide a moisture proof insulating seal. Theinsulation of each conductor is locked together in a plastic resin'thatprotects the connection from the surrounding atmosphere, and issuitablefor use in splicing applications including'those exceeding the7.5 kv. service so long as proper precautions are taken to insure thatadequate insulation is provided by selecting the proper thickness of theresin insulator.

It should now be evident that the several improved resin splicesoutlined above can be applied with equal ease to a wide variety ofstraight or branched connections in both power and communication cables,where the size and thickness of insulation can be adjusted to match theseverity of environment. The use of these procedures permits normallydifiicult splices to be accomplished at the job site even in restrictedworking quarters.

Having thus described the invention, what is claimed and desired to besecured by Letters Patent is:

1. An electrical spider connection comprising-a multiplicity ofseparately insulated branch conductors mechanically and electricallyconnected at a common junction, said branch conductors having anindividual length from said junction of not substantially greater thanfour feet and together forming a short length of multiple stranded cablein which the individual strands are insulated from each other save atsaid junction, means forming a layer of insulation completely coveringsaid junction, and a main conductor projecting from said junction beyondthe exterior of said means.

2. The spider connection of claim 1 in which the individual conductorsare provided with a uniform coating of electrical insulation about theirexterior surface, said insulation extending into said means a sufiicientdepth to provide an hermetic and mechanical connection between adjacentconductors.

3. The spider connection of claim 2 in which the end of the multiplicityof conductors within said .junction each abut a common plane and arerigidly fastened by multiple turns of copper wire tightly wound aboutthe outer periphery of the connected ends and embedded in solder.

4. The spider of claim 2 in which the multiplicity of conductors arecomprised of two. groups of individually insulated conductors, one groupconsisting ofat least one conductor, and the other group consisting ofmore than one conductor, each conductor in the former group having across sectional area equivalent to thetotal cross sectional area of theconductors in the latter group.

5. The spider connection of claim 2 wherein said common junctionincludes a metallic sleeve defining first-and second connection sockets,said branch conductors being crimped into said sleeve at said secondconnection socket, whereby said first connection socket may be connectedto a main service supply and saidmultiplicity of conductors may be usedto supply several branch circuits.

6. The spider of claim 5 in which the, ends ofsaid branch conductorsfurthest removed from the said; common junction are each provided with aplastic cap seal means to thereby hermetically seal the conductor.

7. The spider of claim 2 in which said means forming a layer ofinsulation is an epoxy resin confined in-a cupshaped poly tetra fluoroethylene coated paper container having a depth and diameter of a valueto entirely enclose said soldered connection.

8. The spider of claim 2 wherein the means forming a layer of insulationincludes an embedment of plastic insulation about said permanentelectrical and mechanical 6 connection, and at least some of theinsulation on said References Cited $211523? branch conductors beingembedded in said em- UNITED STATES PATENTS 9. The spider of claim 1wherein said common junc- 2,905,918 9/ 1959 Wagnertion includes ametallic sleeve, crimped onto said conductors said branch conductorsbeing crimped onto said 5 DARRELL CLAY Pnmary Exammer sleeve at saidconnection means, whereby said sleeve may U 8 C1 X R be connected to amain service supply and said multiplici'ty of branch conductors may beused to supply several 17487, 90; 29628 branch circuits. 10

